and (fc.. =. AUCTAM (— ^Si-J 



we can write 



If oo 



(k Q X^ rv IS /i w U T\ r/^c/fl _0 \\u /il^ rl n 



(5.8) 



Using Equation (5.6) for S(K,e,f) we get 



?*(i] = :X K. f E -^p { Uit K„D;jCos (e - i\,..)) 

 = S Ko J C06 (air K„Dij cos (9 - ^ ) de 



de 





+ L?;KojsiM(2irK,D^jCos(e-(t>.^))(i0 



(5.9) 



-1f 



Now, departing from the above development, consider the following 

 integral where 



.If 



\cos(v»e) COS (j5 cos(0-a)))Ae 



-tr 



Let (j) = - i/j and we get 



rC0S(7l(t)+>)qj) C0S(Z COS(|)) 



21 



